Electrical design in plant engineering via rule-based configuration

Time savings of 50–60%

The company Zahnen Technik GmbH is located in Arzfeld/ Eifel, Germany and supports customers nationally and internationally in optimising, modernising and constructing sewerage and water systems. The company has linked the engineering tool EPLAN Engineering Configuration (EEC) to EPLAN Electric P8 and EPLAN Pro Panel and achieved 50–60% time-savings in generating schematics. Designers are now able to use the time saved to focus on applying complex and innovative technologies for the benefit of customers. Higher quality, lower costs, and shorter deadlines: this is the triad of targets in which machine and systems engineering companies find themselves (Fig. 1). The illustration shows that any improvement in one of these three factors unavoidably places pressure on the other two. When improvements are achieved in two, e.g. costs and time, the third suffers, in this case quality. The aim is therefore to find solutions that optimise all three engineering factors equally.

Systems planning and engineering in sewerage and water technology

Only new processes and workflows can alter the dependencies between the triad of targets, so this was the goal that Zahnen Technik GmbH / Germany set itself. The company has been managed by Herbert Zahnen since 1992 and supports customers nationally and internationally in the optimisation, modernisation and new construction of sewerage and water systems – which includes I&C engineering, software programming and establishing links to process control systems. At the end of the design process, Zahnen also undertakes control cabinet construction. The company's in-house steel and pipeline engineering services provide the conditions necessary for component manufacture as well as for the complete overhaul of existing water and sewerage systems – a frequent requirement.

Complex projects

Such a demanding area means that the majority of Zahnen's projects are highly complex. Benedikt Ney (Development at Zahnen Water Engineering Performance): "Each project is very individual. There are no ready-made solutions." (Figs. 2 and 3). The customers in this market are usually public organisations such as local governments and sewerage authorities. Zahnen's rapid corporate growth is evidence of the company's success within the market. Such growth requires continuous updating of internal company workflows, a task which the company takes extremely seriously. Herbert Zahnen: "As a knowledge-based company, we are forcing the pace of technical progress that benefits society. We are currently shifting from being a manual trade to becoming an industrial operation. We have therefore had to, and have to, change our engineering processes accordingly."

Aims: increased workflow consistency – higher level of automation

The aim of such a process of change was clear from the outset: to shift from the planning and designing of control cabinets to automated configuration. Ironically, however, the rapid growth of the company was hindering the first step in such a shift. Herbert Zahnen: "As a user of EPLAN Electric P8, it was clear that we would use EPLAN Engineering Configuration (EEC) as a schematic configurator which we wanted to implement in a consistent IT-based workflow. But we had to be patient with the plan. The company's rapid expansion required relocation to new premises and this had priority." The time was however used to make detailed preparations for implementing EEC. As part of his bachelor dissertation, Benedikt Ney examined the opportunities for an holistic engineering approach. Among other things he compared different systems and came to the conclusion that EEC was in fact the right tool for the task. The subject of his subsequent master dissertation in 2013 was the establishment of a holistic engineering process and partial automation in electrical production. It was only logical that following his course of studies, Benedikt Ney would then implement the project. At this point, EPLAN’s consulting services also became involved. Benedikt Ney: "At the beginning of 2014 we set down a timeplan and milestones and then began defining macros and standards." This meant seeing Zahnen not as a mechanical engineering business but rather as a systems engineering business. "We constantly deal with one-off projects and specialised systems. We aim for standardisation but not at 100% because every project requires specific aspects of individualised engineering. This involves modifications and details whose standardisation and incorporation into modules is not worthwhile because of the insufficient potential for reusability."

Step-by-step towards consistent design

The first step in implementation can be described as "tidying up". Basis projects were jointly defined and the first macro data setup (Fig. 4). Benedikt Ney: "We took reusable components from completed projects. This created a 'module' which is used to assemble our systems." For example, when configuring, designers now select functions such as "temperature measurement", specify them through details on manufacturer, measurement principle and bus system, and links them with other functions and/or components (Fig. 5). At Zahnen Technik, not only was EEC implemented for configuring schematics but also EPLAN Pro Panel which enables 3D-based design and control cabinet layout planning – with a direct link to production. For this purpose, Zahnen had already acquired a new CNC processing centre. Data is transmitted directly from design to CNC-based production. Following this preparatory work, at the beginning of 2015 designers began – with support from EPLAN’s consulting services – a first EEC pilot project which was a major success. Benedikt Ney: "At an organisational level, each project has a project developer who compiles the documentation (structured according to subunits) and transfers it to the designer. The designer uses the EEC module to generate electrical circuits structured according to function." This is the basis for individualised engineering for the specific project, e.g. generation of the control cabinet assembly.

Time savings of 50 to 60%

The seven electrical designers from Zahnen have been working according to this principle since January 2016 – the result is measurable. Benedikt Ney: “In schematic creation we are achieving time savings of 50– 60%. The standard elements are automatically designed which avoids errors from copy and paste:" This means – referring back to the triad of targets – that two of the three core factors have been significantly improved. There are even benefits for the third factor, costs, because working time and therefore working costs have been reduced. EEC at Zahnen has been designed to enable customer standards to be incorporated. These standards are analysed beforehand and then incorporated within EEC. A link to the ERP system enables a consistent workflow in procurement, costing and production planning. Work packages are created already during electrical-design configuration. These contain detailed timeplans to ensure "hardware" progresses through production in a structured way.

Fully applied schematic generator

Zahnen designers are using EPLAN Engineering Configuration (EEC) not just for "pure" electrical engineering, but also for the automated creation of, for example, PLC codes, specifications and documentation. With its new workflow, Zahnen has not only achieved an electrical engineering process that is faster and qualitatively better, but has also established the conditions necessary for the company to offer its customers high-value and innovative systems. Benedikt Ney: "Designers shouldn't be performing repeatable tasks – these should be automated. Designers should instead be using their skills to develop the best technical solutions and making new technologies useful for our customers." This applies equally to the operational safety of systems as well as to efficiency. In this respect, there are always new developments to challenge designers which Zahnen can then apply to offer genuine benefits to the operators of water and sewerage systems. From a customer perspective, standardising processes in organisation significantly increases the ability of Zahnen to deliver individual customer requirements (Fig. 6), thereby completing the circle of benefits.